Cushion for mask system

ABSTRACT

A mouth cushion for a mask system includes a side wall, an undercushion extending away from the side wall, and a membrane provided to substantially surround the undercushion and adapted to form a continuous seal around an exterior of a patient&#39;s mouth in use. The side wall includes spaced-apart prong support structures that provide annular recesses adapted to support respective nasal prongs, and at least a portion of the undercushion includes a question-mark or sickle-shape configuration when in cross-section.

CROSS-REFERENCE TO APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/848,360, filed Oct. 2, 2006, which is incorporated herein byreference in its entirety.

Also, PCT Application No. PCT/AU2006/000770, filed Jun. 6, 2006, andU.S. application Ser. No. 11/447,295, filed Jun. 6, 2006, are eachincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a cushion for a mask system used fortreatment, e.g., of Sleep Disordered Breathing (SDB) with ContinuousPositive Airway Pressure (CPAP) or Non-Invasive Positive PressureVentilation (NIPPV).

BACKGROUND OF THE INVENTION

Mask systems form an interface between a patient and apparatus providinga supply of pressurized air or breathing gas and are hence sometimesreferred to as patient interfaces. In this specification, the words masksystem and patient interface may be used interchangeably. Mask systemsin the field of the invention differ from mask systems used in otherapplications such as aviation and safety in particular because of theiremphasis on comfort. This high level of comfort is desired becausepatients must sleep wearing the masks for hours, possibly each night forthe rest of their lives. Mask systems typically, although not always,comprise (i) a rigid or semi-rigid portion often referred to as a shellor frame, (ii) a soft, patient contacting portion often referred to as acushion, and (iii) some form of headgear to hold the frame and cushionin position. Mask systems often include a mechanism for connecting anair delivery conduit. The air delivery conduit is usually connected to ablower or flow generator.

A range of patient interfaces are known including nasal masks, nose &mouth masks, full face masks and nasal prongs, pillows, nozzles &cannulae. Masks typically cover more of the face than nasal prongs,pillows, nozzles and cannulae. In this specification, all will becollectively referred to as patient interfaces or mask systems. Nasalprongs, nasal pillows, nozzles and cannulae all will be collectivelyreferred to as nasal prongs.

An inherent characteristic of nasal masks is that they do not seal themouth region. A number of patients thus find that during sleep whenmuscles relax, mouth leak may occur. Alternatively, some patients arenaturally mouth breathers and thus find a nasal mask type patientinterface ineffective. Mouth leak is undesirable as, among otherdifficulties, it may result in noise, increased treatment pressure tocompensate for the leak or an increased load on the nasal passages andpotentially nasal obstruction or a runny nose. Full face masks or nose &mouth masks address this issue by sealing around both the nose and themouth.

Leak is a problem common to all designs of patient interface. Sincenasal bridge anthropometry varies greatly between patients, the softpatient contacting portion or cushion must adapt to the shapes ofindividual patients. Typically, this is not achieved for the entirerange of patients and some form of leak occurs. The problem isheightened during sleep when the jaw moves and the head positionchanges. This action can often serve to dislodge the mask and causeleak. Since leak can be noisy and results in less-effective treatment,users often compensate by tightening the headgear more than is desired.This is detrimental for patient comfort and can cause skin breakdown orirritation.

A further problem encountered by patients who are using full face, nasalor nose and mouth masks is that the portion of the patient interfacethat seals around the nasal bridge prevents the patient from wearingspectacles. Additionally, it may give the sensation of being closed in,leading to a feeling of claustrophobia, particularly when combined witha mouth-sealing portion. A further disadvantage is that any leaks thatmay occur can affect the sensitive area surrounding the eyes.

Thus, there is a need for an improved mask system that does not sufferfrom the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a mouth cushion for amask system. The mouth cushion includes a side wall, an undercushionextending away from the side wall, and a membrane provided tosubstantially surround the undercushion and adapted to form a continuousseal around an exterior of a patient's mouth in use. The side wallincludes spaced-apart prong support structures that provide annularrecesses adapted to support respective nasal prongs. Each prong supportstructure includes an alignment indicator to aid correct assembly of therespective nasal prong.

Another aspect of the present invention relates to a mouth cushion for amask system. The mouth cushion includes a side wall, an undercushionextending away from the side wall, and a membrane provided tosubstantially surround the undercushion and adapted to form a continuousseal around an exterior of a patient's mouth in use. The side wallincludes spaced-apart prong support structures that provide annularrecesses adapted to support respective nasal prongs. Each prong supportstructure may includes an alignment indicator to aid correct assembly ofthe respective nasal prong. At least a portion of the undercushionincludes a question-mark or sickle-shape configuration when incross-section.

Another aspect of the present invention relates to a mask system for usebetween a patient and a device to deliver a breathable gas to thepatient. The mask system includes a frame including a channel and acushion provided to the frame. The cushion includes an end portion thatis inserted and retained within the channel. The frame includes a recessthat communicates with the channel and a hole that connects the recessto a frame exterior. The hole and recess provide an exit route for aircontained within the channel.

Another aspect of the present invention relates to a nasal prongarrangement for a mask system. The nasal prong arrangement includes apair of nasal prongs structured to sealingly communicate with nasalpassages of the patient's nose in use. Each of the nasal prongs isadapted to be assembled to a support structure. Each of the nasal prongsincludes at least one marking and/or tab that is adapted to aidalignment of each nasal prong with the support structure.

Another aspect of the present invention relates to a method forassembling a nasal prong to a cushion. The method includes assemblingthe nasal prong to a support structure provided to the cushion, andaligning a marking and/or tab provided to the nasal prong with analignment indicator provided to the support structure.

Another aspect of the present invention relates to a mouth cushion for amask system. The mouth cushion includes a side wall, an undercushionextending away from the side wall, and a membrane provided tosubstantially surround the undercushion and adapted to form a continuousseal around an exterior of a patient's mouth in use. The side wallincludes spaced-apart prong support structures that provide annularrecesses adapted to support respective nasal prongs. At least a portionof the undercushion includes structure to encourage bending in use.

Other aspects, features, and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles of thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the variousembodiments of this invention. In such drawings:

FIGS. 1-1 to 1-3 illustrate various views of a sealing assembly for amask system including a cushion according to an embodiment of thepresent invention;

FIGS. 2-1 to 2-7 illustrate various views of the cushion of the sealingassembly shown in FIGS. 1-1 to 1-3 according to an embodiment of thepresent invention;

FIGS. 3-1 to 3-2 illustrate various views of a frame of the sealingassembly shown in FIGS. 1-1 to 1-3;

FIGS. 4-1 to 4-3 illustrate various views of a cushion according toanother embodiment of the present invention;

FIGS. 5-1 to 5-4 illustrate various views of assembling a cushion to aframe according to an embodiment of the present invention;

FIGS. 6-1 to 6-3 illustrate various views of a sealing assembly for amask system including a cushion according to another embodiment of thepresent invention;

FIG. 7-1 is a perspective view of a paired prong arrangement accordingto an embodiment of the present invention;

FIG. 7-2 is a top view of a mask system illustrating the paired prongarrangement shown in FIG. 7-1 assembled to a cushion according to anembodiment of the present invention;

FIG. 8-1 is a cross-sectional view of a cushion according to anotherembodiment of the present invention;

FIG. 9-1 is a cross-sectional view of a cushion according to anotherembodiment of the present invention;

FIG. 9-2 is a schematic view of a cushion illustrating cross-sectionalconfiguration around its circumference according to an embodiment of thepresent invention; and

FIG. 9-3 is a schematic view of a cushion illustrating cross-sectionalconfiguration around its circumference according to another embodimentof the present invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Each illustrated embodiment includes features that may be used with theembodiments and/or components described in PCT Application No.PCT/AU2006/000770, filed Jun. 6, 2006, and U.S. application Ser. No.11/447,295, filed Jun. 6, 2006, as would be apparent to those ofordinary skill in the art. PCT Application No. PCT/AU2006/000770 andU.S. application Ser. No. 11/447,295 are each incorporated herein byreference in its entirety.

The following illustrates several alternative embodiments of the presentinvention, which may share common characteristics and features. It is tobe understood that one or more features of any one embodiment may becombinable with one or more features of the other embodiments. Inaddition, each single feature or combination of features in any of theembodiments may constitute an additional embodiment.

1. Sealing Assembly

FIGS. 1-1 to 1-3 illustrate a sealing assembly 10 for a mask system thatincludes a cushion 20 according to an embodiment of the presentinvention. The sealing assembly 10 is structured to provide an effectiveseal with both the patient's mouth and the patient's nasal passages inuse. The sealing assembly 10 is adapted to be coupled to an elbowassembly, e.g., swivel elbow, that delivers breathable gas to thepatient, and a headgear assembly that maintains the sealing assembly 10in a desired position on the patient's face.

The sealing assembly 10 includes a mouth cushion 20 structured tosealingly engage around an exterior of a patient's mouth in use and apair of nasal prongs 30 structured to sealingly communicate with thenasal passages of the patient's nose in use. The cushion 20 isstructured to be removably and replaceably attached to a substantiallyrigid frame 40 (see FIGS. 3-1 and 3-2).

Further details and embodiments of this type of mask system includingfurther details and embodiments of nasal prongs and frames are disclosedin the above noted PCT Application No. PCT/AU2006/000770 and U.S.application Ser. No. 11/447,295.

1.1 First Embodiment of Mouth Cushion

FIGS. 2-1 to 2-7 illustrate the mouth cushion 20 of the sealing assemblyaccording to an embodiment of the present invention. As illustrated, themouth cushion 20 includes a face-contacting portion 22 and anon-face-contacting portion 24.

As best shown in FIGS. 2-6 and 2-7, the face-contacting portion 22 ofthe cushion 20 includes a side wall 50, an undercushion 52 extendingaway from the side wall 50, and a membrane 54 provided to substantiallysurround the undercushion 52 and provide a sealing structure for theface-contacting portion 22. The inner edge of the membrane 54 defines anaperture 57 that receives the patient's mouth (see FIGS. 2-1 and 2-3).

The non-face-contacting portion 24 is structured to be removably andreplaceably attached to the frame 40. As best shown in FIGS. 3-1 and3-2, the frame 40 includes a main body 44 having a side frame portion 46on each lateral side thereof. The main body 44 includes an aperture 45and a flanged collar member 47 adapted to engage an elbow. Also, eachside frame portion 46 includes headgear attachment points, e.g., upperand lower anchors 48, 49, for attaching a headgear assembly. Such aframe arrangement is disclosed in the above noted PCT Application No.PCT/AU2006/000770 and U.S. application Ser. No. 11/447,295.

In the illustrated embodiment, the non-face-contacting portion 24includes an arrow-head type design having a tapered end portion 56 witha sealing lip 58 (see FIGS. 2-6 and 2-7). The tapered end portion 56 isadapted to be easily inserted and retained within a channel provided onthe frame 40 in manner as described below.

1.1.1 Alignment Indicators

The side wall 50 of the cushion 20 includes spaced-apart prong supportstructures 60 that provide annular recesses 62 adapted to supportrespective prongs 30. As illustrated, the prong support structures 60provide an angled pedestal that project the prongs 30 at the correctangle to the patient's nares (e.g., see FIGS. 1-1 to 1-2).

Moreover, each prong support structure 60 includes an alignmentindicator 70 to aid correct assembly of the respective prong 30.Specifically, each alignment indicator 70 includes spaced-apart tabs orprotrusions 72. The spaced-apart tabs 72 protrude from a top wall of theprong support structure 60 adjacent the recess 62. Also, the alignmentindicator 70 is provided to a side of the prong support structure 60that is easy visible, e.g., oriented along the side of the cushion 20.

In use, the alignment indicators 70 provide a visual and tactilefeedback system to aid assembly of the prongs 30 to the mouth cushion20. This arrangement may be particularly helpful since the prongs 30 maybe molded straight, e.g., see FIG. 7-1, and then flexed on assembly tothe mouth cushion 20.

In an alternative embodiment, each prong 30 may include a marking thatis adapted to align with a respective alignment indicator 70. In afurther alternative embodiment, each prong 30 may include a tab that isadapted to engage a respective alignment indicator 70 to aid correctassembly. In embodiments, each prong may include multiple markingsand/or multiple tabs that allows one of multiple positions or angles ofthe prong to be selected for assembly.

For example, FIG. 7-1 illustrates a paired-prong arrangement includingprongs 30 joined by a bridging or connecting strap 32. As illustrated,each prong 30 includes a tab 35 that extends radially outwardly from abase portion thereof. When the paired-prong arrangement is assembled tothe cushion 20, as shown in FIG. 7-2, the tab 35 of each prong 30engages a respective alignment indicator 70 to aid correct assembly,e.g., tab 35 extends between the spaced-apart tabs 72. It should beunderstood that such a tab arrangement may be provided to a single-prongarrangement that is molded and assembled individually to the cushion 20.

1.1.2 Cushion Profile

The profile of the cushion 20 is structured to provide a better seal andmay include characteristics and/or features similar to the cushionprofile disclosed in PCT/AU2006/000032, filed Jan. 12, 2006, which isincorporated herein by reference in its entirety.

FIG. 2-6 illustrates a cross-section of the cushion 20 between the prongsupport structures 60. As illustrated, at the upper lip section UL ofthe cushion profile, the side wall 50, undercushion 52, and membrane 54are all generally aligned in a relatively straight profile. However, atthe lower lip section LL of the cushion profile, the lower portion ofthe undercushion 52 has a more arcuate, e.g., semi-circular,question-mark, sickle-shape, configuration that defines a space 55 belowa lower portion of the undercushion 52 and adjacent the side wall 50.This arcuate configuration provides greater flexibility or range ofmovement to the undercushion 52 in use.

That is, the arcuate configuration provides a spring structure thatencourages the cushion wall to resiliently bend rather than buckle. Itshould be appreciated that the cushion wall may have other suitableconfigurations to achieve this spring structure or flexibility, e.g.,arcuate configuration, varying wall thickness, bellows arrangement, etc.

Moreover, this cushion profile provides a seal that accommodates a widerange of facial profiles, facilitates set-up and achievement of a seal,and accommodates movement of the patient's face during use.

The arcuate configuration is also provided at the sides of the cushion20, i.e., in the cheek sections C, as shown in FIG. 2-7. In addition,the cushion 20 may be designed at an angle α steeper than the majorityof facial profiles to provide an initial contact on the cheeks of thepatient and thus ensure a strong seal at these points. In an embodiment,the angle α in FIG. 2-7 may be in the range of 30-50°, e.g., 40°.

Also, FIGS. 2-4 and 2-5 illustrate the cushion 20 (in solid lines) withrespect to a cushion (in dashed lines) disclosed in the above noted PCTApplication No. PCT/AU2006/000770 and U.S. application Ser. No.11/447,295.

1.2 Second Embodiment of Mouth Cushion

FIGS. 4-1 to 4-3 illustrate a cushion 220 according to anotherembodiment of the present invention. In this embodiment, no arcuateconfiguration is provided over a short distance at the upper lip andlower lip sections UL, LL of the cushion profile. The arcuateconfiguration is provided at the sides of the cushion 220, which thenslowly blends to a flat configuration over a short distance at the topand bottom lip sections.

Specifically, as shown in FIG. 4-2, the side wall 250, undercushion 252,and membrane 254 at the upper lip and lower lip sections UL, LL are allgenerally aligned in a relatively straight profile. As shown in FIG.4-3, the lower portion of the undercushion 252 at the cheek sections Chas a more arcuate, e.g., semi-circular, question-mark, sickle-shape,configuration that provides greater flexibility to the undercushion 252in use.

The combination of the arcuate configuration at the cheek sections C anda steeper cushion angle previously discussed provide an improved sealand fit of the cushion 220. The arcuate configuration at the cheeksections C of the cushion 220 are typically the first section of thecushion 220 to contact the patient's face and the arcuate configurationat the cheek sections C then deform as required to allow the cushion 220to be fitted to the upper lip and lower lip sections UL, LL. The lastpoints of contact are thus the more sensitive areas of the patient'sface, i.e., the upper lip and lower lip sections UL, LL. Theadjustability in the cheek regions C provided by the arcuateconfiguration allows the patient to finely adjust the cushion 220 tocomfortably fit and seal in these sensitive regions of the upper lip andlower lip sections UL, LL while still maintaining a cheek seal withoutexcessive force.

1.3 Cushion Assembly to Frame

FIGS. 5-1 to 5-4 illustrate assembly of a cushion to a frame accordingto an embodiment of the present invention. In the illustratedembodiment, the cushion is in the form of cushion 220 described aboveand indicated with similar reference numerals. The frame 240 is similarto frame 40 described above. In contrast, the frame 240 includes twoports 242, e.g., tubular spigots, located in recesses in the base of theframe 240. It should be appreciated that cushion 20 may be attached toframe 240 in a similar manner, and that cushions 20, 220 may be attachedto frame 40 in a similar manner.

As illustrated, the tapered end portion 256 is adapted to be easilyinserted and retained within a channel 280 provided on the frame 240.The sealing lip 258 provides a seal around the perimeter of the cushion220 and also in conjunction with the bead 282 (see FIG. 5-4) around theframe channel 280 retains the cushion 220 onto the frame 240.

In addition, a recess 285 is provided to the frame 240 and communicateswith the channel 280 that retains the cushion 220, as best shown in FIG.5-4. The recess 285 forms a smaller channel around the bottom of thechannel 280. Also, a hole 290 is provided below the ports 242 whichconnects the recess or channel 285 to the exterior of the frame 240 (seeFIGS. 5-1, 5-2, and 5-4). It should be appreciated that the hole 290 maybe located at any position around the channel 280.

In manufacturing assembly, a vacuum is applied around the hole 290 whichin turn creates a vacuum around the channel 285 drawing the cushion 220into the fully seated position. The hole 290 and channel 285 also helpstandard assembly by allowing an exit route for the air contained withinchannel 280 and thus leading to less force required to assemble thecushion 220 to the frame 240. In this embodiment, the channel 285 has atapered hole, e.g., exit diameter about 1.0-1.3 mm, e.g., 1.16 mm. Inalternative embodiments, the hole diameter may vary and multiple holesand/or a deeper/varying section channel may be provided.

1.4 Third Embodiment of Mouth Cushion

FIGS. 6-1 to 6-3 illustrate a cushion 320 according to anotherembodiment of the present invention. In this embodiment, each side ofthe cushion 330 includes a support strut or rib 325. As illustrated, thesupport strut 325 extends generally horizontally along an exteriorsurface of the respective side of the cushion 320. In use, the supportstrut 325 may modify the deflection characteristic of the cushion 320.It should be appreciated that the support strut 325 may have othersuitable shapes, arrangements, and positioning along the cushion 320 tomodify the deflection characteristic. In addition, one or more supportstruts may be provided to modify the deflection characteristic.

1.5 Alternative Embodiments of Mouth Cushion

FIG. 8-1 illustrates a cross-section of a mouth cushion 420 according toan alternative embodiment of the present invention. As illustrated, thecushion cross-section includes a side wall 450, undercushion 452, andmembrane 454. The undercushion 452 has a more arcuate, e.g.,semi-circular, question-mark, sickle-shape, configuration (e.g., in thelower lip section) that provides flexibility to the cushion 420 withoutextending the footprint of the cushion 420. That is, the cushion 420 mayretain the same overall height.

FIG. 9-1 illustrates a cross-section of a mouth cushion 520 according toanother alternative embodiment of the present invention. As illustrated,the cushion cross-section includes a side wall 550, undercushion 552,and membrane 554. The undercushion 552 has a more arcuate, e.g.,semi-circular, question-mark, sickle-shape, configuration that providesflexibility to the cushion 520.

In an embodiment, the arcuate configuration, e.g., sickle-shapedcross-section, may be provided around a majority of the cushioncircumference, as shown in a bold line in FIG. 9-2. Alternatively, thearcuate configuration, e.g., sickle-shaped cross-section, may beprovided around the entirety of the cushion circumference, as shown in abold line in FIG. 9-3. Depending on the radius of curvature of thearcuate shape, this arrangement may have a contact point on thepatient's face outside of that which would be achieved with a cushionhaving a cross-section such as that shown in FIG. 4-2 for example. Thisallows the frame to be smaller, thereby providing less weight andvisually reducing the mask for the patient.

While the invention has been described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention. Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. Further, each independent feature orcomponent of any given assembly may constitute an additional embodiment.In addition, while the invention has particular application to patientswho suffer from OSA, it is to be appreciated that patients who sufferfrom other illnesses (e.g., congestive heart failure, diabetes, morbidobesity, stroke, bariatric surgery, etc.) can derive benefit from theabove teachings. Moreover, the above teachings have applicability withpatients and non-patients alike.

1-10. (canceled)
 11. A mouth cushion for a mask system, the mouth cushion comprising: a side wall; an undercushion extending away from the side wall; and a membrane provided to substantially surround the undercushion and adapted to form a continuous seal around an exterior of a patient's mouth in use, wherein the side wall includes spaced-apart prong support structures that provide annular recesses adapted to support respective nasal prongs, and at least a portion of the undercushion includes a question-mark or sickle-shape configuration when in cross-section.
 12. The mouth cushion according to claim 11, wherein the undercushion includes a question-mark or sickle-shape configuration in a lower lip section.
 13. The mouth cushion according to claim 11, wherein the undercushion includes a question-mark or sickle-shape configuration in cheek sections.
 14. The mouth cushion according to claim 11, wherein the membrane in each cheek section defines an angle with respect to a longitudinal axis of about 30-50°.
 15. The mouth cushion according to claim 14, wherein the membrane in each cheek section defines an angle with respect to a longitudinal axis of about 40°.
 16. A mask system for use between a patient and a device to deliver a breathable gas to the patient, the mask system comprising: a frame; a mouth cushion according to claim 11 provided to the frame; and a pair of nasal prongs provided to respective prong support structures of the mouth cushion.
 17. The mask system according to claim 16, wherein each prong includes a tab that engages a respective alignment indicator provided to the mouth cushion.
 18. The mask system according to claim 16, wherein the mouth cushion includes a tapered end portion with a sealing lip, the tapered end portion adapted to be inserted and retained within a channel provided to the frame.
 19. The mask system according to claim 18, wherein the sealing lip provides a seal around the perimeter of the cushion.
 20. The mask system according to claim 18, wherein the frame includes a recess that communicates with the channel and a hole that connects the recess to a frame exterior.
 21. The mask system according to claim 20, wherein the hole and recess provide an exit route for air contained within the channel.
 22. The mask system according to claim 20, wherein the recess is tapered. 23-25. (canceled)
 26. A mouth cushion for a mask system, the mouth cushion comprising: a side wall; an undercushion extending away from the side wall; and a membrane provided to substantially surround the undercushion and adapted to form a continuous seal around an exterior of a patient's mouth in use, wherein the side wall includes spaced-apart prong support structures that provide annular recesses adapted to support respective nasal prongs, and at least a portion of the undercushion includes structure to encourage bending in use.
 27. A cushion for a respiratory mask used in treatment of sleep disordered breathing including a sidewall portion defining a spring structure arranged to progressively resiliently bend in use.
 28. The cushion of claim 27 wherein the sidewall portion has a sickle shape.
 29. The cushion of claim 27 wherein the sidewall portion is designed to progressively bend rather than buckle in use. 